Coating provides extra layer of protection for battery cathodes.
Building a better lithium-ion battery involves addressing a myriad of factors simultaneously, from keeping the battery's cathode electrically and ionically conductive to making sure that the battery stays safe after many cycles.
In a new discovery, scientists at the U.S. Department of Energy's (DOE) Argonne National Laboratory have developed a new cathode coating by using an oxidative chemical vapor deposition technique that can help solve these and several other potential issues with lithium-ion batteries all in one stroke.
"The coating we've discovered really hits five or six birds with one stone." Khalil Amine, Argonne distinguished fellow and battery scientist.
In the research, Amine and his fellow researchers took particles of Argonne's pioneering nickel-manganese-cobalt (NMC) cathode material and encapsulated them with a sulfur-containing polymer called PEDOT. This polymer provides the cathode a layer of protection from the battery's electrolyte as the battery charges and discharges.
Unlike conventional coatings, which only protect the exterior surface of the micron-sized cathode particles and leave the interior vulnerable to cracking, the PEDOT coating had the ability to penetrate to the cathode particle's interior, adding an additional layer of shielding.
In addition, although PEDOT prevents the chemical interaction between the battery and the electrolyte, it does allow for the necessary transport of lithium ions and electrons that the battery requires in order to function.
"This coating is essentially friendly to all of the processes and chemistry that makes the battery work and unfriendly to all of the potential reactions that would cause the battery to degrade or malfunction," said Argonne chemist Guiliang Xu, the first author of the research.
The coating also largely prevents another reaction that causes the battery's cathode to deactivate. In this reaction, the cathode material converts to another form called spinel. "The combination of almost no spinel formation with its other properties makes this coating a very exciting material," Amine said.
The PEDOT material also demonstrated the ability to prevent oxygen release, a major factor for the degradation of NMC cathode materials at high voltage. "This PEDOT coating was also found to be able to suppress oxygen release during charging, which leads to better structural stability and also improves safety," Amine said.
Amine indicated that battery scientists could likely scale up the coating for use in nickel-rich NMC-containing batteries. "This polymer has been around for a while, but we were still surprised to see that it has all of the encouraging effects that it does," he said.
With the coating applied, the researchers believe that the NMC-containing batteries could either run at higher voltages -- thus increasing their energy output -- or have longer lifetimes, or both.
"The coating we've discovered really hits five or six birds with one stone," said Argonne distinguished fellow and battery scientist Khalil Amine, who led the research.
To perform the research, the scientists relied on two DOE Office of Science User Facilities located at Argonne: the Advanced Photon Source (APS) and the Center for Nanoscale Materials (CNM). In situ high-energy X-ray diffraction measurements were taken at beamline 11-ID-C of the APS, and focused ion beam lithography and transmission electron microscopy were performed at the CNM.
A paper based on the study, "Building ultra-conformal protective layers on both secondary and primary particles of layered lithium transition metal oxide cathodes," appeared in the May 13 online edition of Nature Energy. Other Argonne authors included Yuzi Liu, Xiang Liu, Han Gao, Minghao Zhuang, Yang Ren and Zonghai Chen. Researchers from Drexel University, Indiana University-Purdue University Indianapolis, and four Chinese universities also collaborated.
The research was funded by DOE's Office of Science, Office of Basic Energy Sciences and the Office of Energy Efficiency and Renewable Energy, Vehicle Technologies Office.
The Office of Energy Efficiency and Renewable Energy supports early-stage research and development of energy efficiency and renewable energy technologies to strengthen U.S. economic growth, energy security, and environmental quality.
Argonne National Laboratory seeks solutions to pressing national problems in science and technology. The nation's first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their specific problems, advance America's scientific leadership and prepare the nation for a better future. With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy's Office of Science.
The U.S. Department of Energy's Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit the Office of Science website.
Benjamin Schiltz | EurekAlert!
Scientists' design discovery doubles conductivity of indium oxide transparent coatings
18.09.2019 | University of Liverpool
Heat shields for economical aircrafts
18.09.2019 | Fraunhofer-Institut für Werkstoff- und Strahltechnik IWS
How long the battery of your phone or computer lasts depends on how many lithium ions can be stored in the battery's negative electrode material. If the battery runs out of these ions, it can't generate an electrical current to run a device and ultimately fails.
Materials with a higher lithium ion storage capacity are either too heavy or the wrong shape to replace graphite, the electrode material currently used in...
To process information, photons must interact. However, these tiny packets of light want nothing to do with each other, each passing by without altering the...
Researchers from the Department of Atomically Resolved Dynamics of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg, the University of Hamburg and the European Molecular Biology Laboratory (EMBL) outstation in the city have developed a new method to watch biomolecules at work. This method dramatically simplifies starting enzymatic reactions by mixing a cocktail of small amounts of liquids with protein crystals. Determination of the protein structures at different times after mixing can be assembled into a time-lapse sequence that shows the molecular foundations of biology.
The functions of biomolecules are determined by their motions and structural changes. Yet it is a formidable challenge to understand these dynamic motions.
At the International Symposium on Automotive Lighting 2019 (ISAL) in Darmstadt from September 23 to 25, 2019, the Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, a provider of research and development services in the field of organic electronics, will present OLED light strips of any length with additional functionalities for the first time at booth no. 37.
Almost everyone is familiar with light strips for interior design. LED strips are available by the metre in DIY stores around the corner and are just as often...
Later during this century, around 2060, a paradigm shift in global energy consumption is expected: we will spend more energy for cooling than for heating....
19.09.2019 | Event News
10.09.2019 | Event News
04.09.2019 | Event News
20.09.2019 | Life Sciences
20.09.2019 | Life Sciences
20.09.2019 | Life Sciences